If my fiance is not a US citizen but we plan on living in the US, where should we get married?

Although not clear from your question, I presume that you, yourself, are a U.S. citizen. If that is true, then the location of your wedding is not central to eligibility for your wife to become a Permanent Resident (to get a "Green Card"), but location of the wedding may dictate how long it may take for your wife to be able to enter the U.S. and to become a Permanent Resident. One option would be for you to petition for your wife to receive a K-1 fiance visa to facilitate her coming to the U.S. to become married to you within the required time, and then to apply for adjustment of status. Other options might include becoming married abroad, and then "consular processing" for her to enter the U.S. as the spouse of a U.S. citizen. Another option would be to explore whether your fiance may be eligible for a different type of nonimmigrant visa that would authorize her to come to the U.S. despite having an intention to remain permanently-that would exclude, for example, a visitor's visa or a student visa. Some immigration law firms, including mine, offer legal services on a "flat fee" basis so that a client will know the total expense from the very beginning, and a few immigration law firms, including mine, offer an initial consultation free of charge.